Patent Document 1 (JP-A No. 2010-207898) discloses a structure where, as different types of materials, a panel made of iron and a panel made of aluminum alloy are joined to one another using a rivet. In this structure, a shaft portion of the rivet is passed through the panel made of aluminum alloy, the distal end of the shaft portion of the rivet is brought into contact with the panel made of iron, and in this state the shaft portion of the rivet and the panel made of iron are joined to one another by spot welding.